Spring operated flashlamp synchronizer having automatic resetting means



J. A. VAN LAMMEREN NC- OPERATED FLASHLAMP SYNCHRONIZER HAV C RESETTING MEANS April 4, 1950 SPRI UTOMAT 2 Sheets-Sheet l Filed July 3, 1946 if (i 54 66 67 ff! April 4, 1950 J. A. VAN LAMMr-:REN 2,502,541

SPRING OPERATED FLASHLANP SYNCHRONIZER HAVING AUTOMATIC RESETTING MEANS Filed July s, 194e 2 sheets-sheet 2 Patented Apr. 4, 1950 SPRING oPERA'rED FLASHLAMP sYNoI-mo- Nlznn HAVING AUTOMATIC REsET'rING MEANS Johannes Antonius van Lammeren, Eindhoven, Netherlands, assignor to Hartford National Bank and: Trust Company, Hartford, Conn., as

trustee Application July 3, 1946, Serial No. 681,382 In the Netherlands October 6, 1943 Section l, Public Law 690, August 8, 1946- Patent expires October 6, 1963 (Cl. S35-11.5)

5 Claims. l.

When taking photographs with a camera by the light radiated by a flash-light lamp, there arises the problem that the flash-light lamp must be ignited; at' a moment chosen very carefully in accordance with the moment when the shutter of the camera is opened, since flash-light lamps, according to the type of'the lamp, have a shorter or longer time of starting, i. e. that the time interval which elapses between the moment when the lamp' is ignited andthe moment when such a lamp radiates its maximum light intensity has a shorter or longer value. The lamp never radiates its' maximum light intensity at the moment of ignition. Consequently, the shutter of the camera by means of which a photograph must be taken' by the light of a flash-light lamp must always be operated after the moment of ignition of the lamp; in order to have the maximum emciency of the light of the lamp. The manufacturers of flash-light lamps furnish data about this starting time with the lamps, so that theA user only has to take care that in taking a photograph the time interval between the ignition of the lamp and the opening of the shutter of his camera is" chosen correctly in accordance with these data. Since with these time intervals very small values are concerned, it is practically not feasible, at leastY if one wishes to be sure to have the maximumreilciency of the flash-light lamp, to obtain the optimum moment of opening of the shutter after the' ignition of the lamp without the use of any further' expedients. In practice one invariably utilizes a so-called synchronizer, that is a device comprising anl electric contact mechanism for igniting a flashlight lamp and' comprising another mechanism which is controlled by the said contact mechanism and whichserves to operate' the shutter of the camera so as to open the shutter at' a variable moment after the ignition of the flash-light lamp, the contact mechanism and the operating mechanism for the shutter being operated bythe same operating knob.

A known device of this kind is constructed in such manner that on pushing anv operating knob the gniting mechanism for the flash-light lamp is operated and the shutter is opened at a variable moment thereafter, but after a photograph has been taken the shutter mechanism and the contact mechanism must be broughtv back into their initial positions by a particular movement of the hand. It is evident that the working with such a device is thus comparatively complicated and takes up much time,which means an importantv drawback since synchronizers are frequently uti- 2, lized for reporting purposes, and for press-photographers and persons working in related elds it is of utmost importance to be able to take several' photographs as quickly as possible in succession. The known synchronizer construction has the additional drawback that, after having taken a photograph, one forgets to reset the synchronizer, so that the mechanism will not work smoothly andthe results will be unsatisfactory.

The present invention obviates this drawback. The device of the above-mentioned kind according to the invention has the feature that the operati'ng knob cooperates with a spring so as to accumulate energy in the latter when operating the knob, which energy, after the shutter has been opened and the hash-light lamp is ignited, is utilised to bring the operating knob, the operating mechanism for the shutter and the electric contact device back into theirl initial positions.

As compared with known synchronizers, the device according. to the invention thus offers the advantage of being immediately ready to be used again after'the operating knob has been released and Without any` further manipulations being required. i

In an advantageous form of construction of the device according to the invention its contact mechanism for the flash-light lamp comprises a rotary operating member having secured to it a spring which can release as a result of pushin'g' of the operating knob, thus causing rotation of the operatingmembenwhile during the returnrof the operating knob after the flash-light lamp has been ignited` andthe shutter has been opened the spring of` the Contact mechanism is the operating mechanism for the shutter there is interposedanadditional spring which is compressedon pushing the operatingknob and which, after the operatingV member for the contact mechanism has been movedv throughl a certaindistance, is released by a pawl operated thereby and can open-the shuttenwhile during the re-y turn of the'operating knob to its position of rest the operating" member for the shutter is brought back by a stop providedatthe side of? the operatingknobas hereinafter' described.

In order that the invention may be more clearly understood and readily carried into effect, it will be described more fully by reference to the accompanying drawings.

Fig. l shows a form of construction of a device according to the invention, with one of the Walls removed so that the interior parts are visible.

Fig. 2 shows a detail of a stop provided at this device.

Figure 3 is a View of the other side of lthe device shown in Figure 1, the adjusting member for the synchronizer being in the position which is used when the synchronizer has to ignite a flash-light lamp having a long starting time.

Figure 4 shows diagrammatically the position oi the adjusting member for the synchronizer, if the synchronizer has to ignite a lamp having a short starting time, and

Figure 5 shows the synchronizer of Figure 4 at the moment when the circuit for the hash-light lamp is closed.

Inside the housing 50 of the synchronizer shown there are arranged three shafts, viz. the shafts I3, I9 and 24. About the shaft I3 a bellcrank lever I2 is rotatably mounted having an arm Il which extends to the left and lies in the path of a stop 53 provided on the outside of an operating knob I (see also Figure 2). The operating knob I is slidably supported in the housing 5I) of the synchronizer. The bell-crank lever I2 further carries an arm I6 which terminates in a cam I5 which engages in a correspondingly shaped recess I'I provided in a disc-shaped member I8. The latter is rotatably mounted on f.

the shaft I9 already referred to. Under the action of a spring 54 the bell-crank-lever I2 is held in its position of rest in such a manner that the cam I5 lies in the recess Il.

As already mentioned, the disc-shaped member I8 is rotatably mounted on the shaft I9 and is further rigidly coupled to a pinion 2l. The shaft I9 is surrounded by a spring 2l] which is secured to the disc I8 so as to tend to rotate the said disc in the direction of the arrow I. In the position of rest this movement is prevented, however, due to the cam I5 and the recess I1 engaging each other. A Contact member 68 provided with a protruding Contact tag 65 is secured to the back of the disc I8 by means of two rivets 66 and 61, said contact member upon rotation of this disc being capable of closing an electric contact in cooperation with a sector-shaped contact member 55 secured to the inside of a cover 56 of insulating material which is rotatably arranged in the housing 50 and serves as an adjusting member (see Figure 3).

The disc I8 further comprises a stop 22 having the form of a pin protruding from the disc I8 and designed to cooperate with the cam-stop portion 5T provided at one end of a bell-crank lever 23 which is rotatable about the shaft 24. At its other extremity the bell-crank lever 23 carries a cam 1 which engages in the interior of knob I by means of a recess 58 extending in the longitudinal direction of this knob. In the position of rest the bell-crank lever 23 is pulled in the direction of the arrow II by means of a spring 58. Consequently, in the position of rest of this lever the cam 'I lies in the path of the operating member =2 for the shutter, which is telescopically movable in the operating knob I, the collar 5 provided at the member 2 serving as a stop against the cam 1.

The shaft 24 hasv further rotatably mounted on it a bel1-crank lever 6U formed at one end as a rim of gear wheel 9 which meshes with the pinion 2i, its outer arm 8 cooperating with a stop IU provided on the outside of the operating knob I.

As previously mentioned, the operating member 2 for the shutter is telescopically movable in the operating knob I. Between the extremity 6I of the member 2, which serves as a stop, and the inside 52 of the operating knob I lies a compression spring 3. Furthermore, on the outside of the operating knob I there is provided a compression spring 4 whose lower end bears against the fixed protrusion 5, serving as a stop, of the housing of the synchronizer and whose upper end engages with the collar 63 provided on the operating knob I. The lower end of the member 2 is secured to the rear end of a Bowden cable 2l which serves as the operating cable for the shutter. The lower end of the member 2 is provided with a collar 2a. Between this collar and a collar 58a of the housing 5|] lies a compression spring l26 which serves as a cushion when the member 2 is moved downwards.

The operation of the device shown in the figures is as follows:

When in taking a photograph with the aid of a flash-light lamp the moment of opening of the shutter of this camera is desired to be, for example, 30 milliseconds later than the moment of ignition of the flash-light lamp, in order thus to have the maximum efliciency of the light radiated by the iiash-light lamp, this moment is adjusted on the division of scale 64 by means of a handle 69 provided on the cover 56 which is rotatable in the housing 50 and serves as an adjusting member. The contact strip 55 on the cover 56 serving as the adjusting member thus acquires a definite position with respect to the contact member 65 on the disc I8. Subsequently, the operating knob I is pushed, whereby both the spring 3 and the spring 4 are compressed. Since during this manipulation the collar 6 immediately abuts against the cam 1, the operating knob I will` While the Bowden cable 21 still occupies its position of rest and hence the camera shutter is still closed, the stop 53 on the side of the knob I engages at a definite moment with the arm II of the lever I2, pushing it in the direction of the arrow I'II against the action of the spring 54. Consequently, the cam I5 disengages from the recess I'I of the disc I8, and this disc can begin to rotate in the direction of the arrow I under the action of the spring 20 which is under tension. The contact member B5 then makes electric contact with the contact strip 55 at the moment pre-adjusted with the aid of the rotary cover 5B, whereupon the iiash-light lamp, which is supplied, for example, by a dry-battery is ignited, since the contacts 65 and 55 are connected to the electric conductors IU and 'II for example, via sliding contacts. Said conductors constitute one conductor of the electric circuit under consideration, the other being constituted by the housing of the synchronizer, which thus serves as a ground.

Upon rotation of the disc i8 the stop 22, after having been turned through nearly 360, engages. with the cam-stop portion 51 of the bell-crank lever 23, due to which the latter is turned in the direction of the arrow IV against the action of.'

the: spring 59. Thisv results in that the cam 1 in front of the. collar 6 of the member 2 is pulled away from the member 2 and the spring 59 is flexed andthe Bowden cable 21, somewhat braked by the cushioning spring 26 is pushed to the exterior. At this moment the shutterv of' the camera is. opened (and closed again). The. photograph is no w taken. During the rotation of the pinion 2| the rim of gear wheel 9 has followed the movement of' this pinion and the bell-crank. lever 60 has moved in the direction of the arrow V. Consequently, the arm 8v of the knee-lever` 60 has followed the movement of the stop IEII, though somewhat retarded.

When now. since the photograph is taken, the operating knob If is released the springs 3 and 4 are enabled to release again, which results: in the. operating knob I' and the member 2 moving upwards. During this movement of the operating, knob I- the movement ol the stop I is iollowedy by the arm. of thebellf-crank lever GIB, in thev direction of the arrow VI, due to which the rim ofv gearV wheel 9, the pinion 2| and hence also the disc lf; move in the direction of the arrow VII. During this movement the spring 2-0. is put under tension again. At the moment when the operating knob I moves upwards they pressure exerted on the arm Il of the 1 bell crank lever I2 releases, due to which under the action of the-spring 54 this bell-crank lever moves in the direction of the arrow VIII. The lower end` of the cam I5 runs on the outer surface of the. disc I8` until the cam I5 snaps into the recess I1. During the same period of time the camstop portion` 51 of the bell-cranklever 23 has disengaged from the stop` 22 on the disc I8, due to which under the action of the spring 59 the bell-crank'lever 23 is moving again in the direction of the arrow II and the cam 1,. due to the recess 58A in the operating member l., engages again behind the collar 6 when the latter has arrived in its position of rest.

For a good understanding of. the operation of the synchronizer it is mentioned that the time interval which el'apse-s between the actuation of the-bell-crank lever I2 to release the disc member I8 from the holdingl action of cam I5v and the moment when the shutter of the camera is opened invariably has the same value, i. e. is constant regardless of mechanicalvadjustments of the synchronizer. In order to` render the synchronizert for lamps having av short or long starting time,k means must betaken in such a synchronizer which determine the momentv of ignition of the hash-light lamp at an adjustable moment before the moment ofopening of the' shutter determined by the pushing of the operating member. These means are shown in detail in Figures 3, 4, and 5'.

As previously mentioned, the circuit includingl thel flash-light lamp is closed by the contact member 65 in cooperation with the contact member provided on the cover 56, serving as the adjusting' member, off the synchronizer housing.

By turning the cover 56 by means of the handle- 59 it is possiblel to Vary the moment in which the -contact member contacts with the contact strip 55. In this connection it is mentioned that'the Contact member 65'which, as previouslyl observed, is fastened on thedisc I8 with theaid of: rivets 66 and. 61,l occupies its position of rest in the position shown in Figures?, and 4", whereas Figure 5- shows the position of the contact member 55 -at'the-moment when it contacts with thecontactv stripl 55.

Since the disc |8 always begins to rotate aty the same moment after pushing the operating. knob l and, as mentioned before, the time interval between the opening of the camera shutter position of the adjusting member shown in Fig-v ure 3, in which the `angle through which the contact member 65 turns (according to this figure to the left) before it contacts with the con-tact strip 55', is approximately 45. On'v the other hand, the adjustment of the adjusting member 56 shown in Figurev 4 is designed for a lamp having. a short starting time, sof that in this casel the angle of rotation of the contact member 615,V

before making electric contact with the contact strip 55,. is much larger' than that in Figure 3 andl in this oase is approximately This angle is adjustable with the aid of they divisions of scale 64.

From Figure 5 it can be seen how the position of the Contact member 65 with respect to the contact strip 55 will be Lat the moment when the electric contact is closed.

What I claim is:

l. In aI photographic synchronizer unit. having. a shutter actuator for the camera, an electric contact mechanism for. igniting. a ilash'light, timing means for synchronizing the shutter actua-f tion with the peak radiation'y of the flashlight, a system of: mechanically controlledl'atch levers, and a common operating member for the con@ trol of the shutter actuator, the contact mechanism, and said levers, in combination means for autoniaticallyy resetting after each exposure, said' shutter actuator, said contact mechanism and timing means, said latch-levers, and the commonI operating member for all said elements, said resetting means comprising spring meansA and ten-- sioning means for the same, said tensioning means having a member capable ofunlockingv during theA operating move the oney of said latchlevers in control of the contact mechanism, saidl contact` mechanism comprising a rotatable discand spring means secured to said disc and becoming operative upon the unlocking of said latch-lever for rotating said disc` overa predeter; mined angle, means on said disc forv engaging a second one of said latch-levers andv thereby turning the same so as to release the shutter actuator in predetermined timefinterval after the ignition'` ofthe flashlight, said tensioning means being adapted on its return move to effect the operation ofsaid levers and their return to lockedposition in reverse, thereby resetting the shutter actuator and the contact mechanism, said' return move of said tensioning means to starting position occurring automatically after exposure by means of the energy stored in said' tensioned spring means.

2. In a photographic synchronizer'unit having a shutter actuator or thel camera, an' electric contact mechanism for igniting the flashlight, timing means for synchronizing the shutter actu'- ation with the peak radiation of said iiashlight, and a combined operating and automatic resetting mechanism for the-shutter actuator and the contact mechanism, said combined operating and resetting mechanismcomprising a first spring' and a member for tensioningsaidf spring, said springy uponl tensioning being adaptedA4 tooperat'er the shutter actuator, means for normally holding said shutter actuator against actuating movement, a second spring for controlling said contact mechanism, said contact mechanism including a rotatable disc to which said second spring is secured at one end, the other end of said spring being secured to a stationary member, said second spring being loaded in normal position and tending to rotate said disc, means for holding said disc of said Contact mechanism against rotation and capable of releasing the same for rotation, a tripping member on said spring tensioning means which upon operation of said means is capable of unlocking the disc-holding means, an element on said disc capable after rotation thereof to engage said holding means for the shutter actuator and of withdrawing it from holding position, and a third spring tensioned upon movement of said rst spring by said tensioning member and adapted to store energy which upon cessation of the tensioning force becomes active for automatically restoring to normal positions the spring tensioning member, the shutter actuating and contact mechanisms and the holding means for both'mechanisms, and for reloading the spring for rotating the disc of the contact mechanism.

3. In a photographic synchronizer unit having an actuator for the camera, an electric contact mechanism for igniting the flashlight, timing means for synchronizing the shutter actuation with the peak radiation oi said flashlight, and a combined common operating and automatic resetting mechanism for the shutter actuator and the contact mechanism, said combined operating `and resetting mechanism comprising a iirst spring and a member for tensioning said spring, said spring upon tensioning being adapted to operate the shutter actuator, means for normally holding said shutter actuator against actuating movement, a second spring for controlling said Contact mechanism, said contact mechanism including a rotatable disc to which said second spring is secured at one end, the other end of said spring being secured to a stationary member, said second spring being loaded in normal position and tending to rotate said disc, means for holding said disc of said contact mechanism against rotation and capable of releasing the same for rotation, a tripping member on said spring tensioning means which upon operation of said means is capable of unlocking the disc-holding means, an element on said disc capable after rotation thereof to engage said holding means for the shutter actuator and of withdrawing it from holding position, and a third spring tensioned upon movement of said iirst spring by said tensioning member and adapted to store energy which upon cessation of the tensioning force becomes active for automatically restoring to normal positions the spring tensioning member, the shutter actuating and contact mechanisms and the holding means for both mechanisms and a connection interposed between said spring tensioning member and said contact mechanism which permitsthe spring tensioning member to overrun the contact mechanism on the operating move and is adapted to reload the spring associated with the contact mechanism on the return move of the spring tensioning member.

4. In a photographic synchronizer unit having a shutter actuator for the camera, an electric contact mechanism for igniting the ashlight, timing means for synchronizing the shutter actuation with the peak radiation of said iiashlight, and a combined common operating and automatic 8 resetting mechanism for-the shutter actuator and the contact mechanism, said combined operating and resetting mechanism comprising a rst spring and a member for tensioning saidf` spring, said spring upon tensioning being adapted to operate the shutter actuator, means for holding saidfshutter actuator against actuating movement, a second spring for controlling said contact mechanism, said contact mechanism including a rotatable disc to which said second spring is secured at one end, the other end of said spring being secured to a stationary member, said secondl spring being loaded in normal position and tend'- ing to rotate said disc, means for holding said disc of said contact mechanism against rotation and capable of releasing the same for rotation, a tripping member on said spring tensioning means' which upon operationy of said means is capable of unlocking the disc-holding means, an element on said disc capable after rotation thereof to engage said holding means for the shutter actuator and of withdrawing it from holding position, and ya third spring tensioned upon movement of said' first spring by said tensioning member and adapted to store energy which upon cessation of the tensioning force becomes active for restoring to normal positions, the spring tensioning member, the shutter yactuating and contact mechanisms and the holding means for both mechanisms, and a connection interposed between said spring tensioning member and said contact mechanism which permits the spring tensioning member to overrun the contact mechanism on the capable of meshing with a pinion secured to the disc mounting shaft and capable of reloading said spring for disc rotation when on the return stroke of said spring tensioning means said stop engages said one arm and thereby rotates the` pinion by gear engagement with said other arm,

5. In a photographic synchronizing system, apparatus for opening the shutter of a camera in timed relation with respect to the peak radiation of la flash-lamp having a shutter opening mechanism which functions on a constant time interval after being set in motion, adjustable electric contacting mechanism comprising a pair of contact members one fixed and the other movable, means for closing said contacts at a predetermined time interval depending upon their relative setting, and a combined operating and automatic resetting mechanism for the shutter actuating and electric contact mechanisms, said combined.

Adisc carrying said movable contact, said disc being under the inuence of a normally loaded spring, said bell-crank mechanism being actuated by said contact mechanism relative to the closing of the electric contact, and a spring tensioned upon movementJ of said first spring by said knob member and adapted to store energy which upon cessation of the tensioning force becomes active for automatically restoring to normal position the knob member, the piston, the piston arresting mechanism, the electric contact mechanism, the timing mechanism therefor, the holding means associated with said mechanisms and for reloading the spring inuencing the disc of the timing mechanism, said spring-reloading means comprising a connection interposed between said spring tensioning member and said Contact mechanism which permits the spring tensioning member to overrun the contact mechanism on the operating 10 move and includes a lever actuated on the return move and capable of rewinding the said spring influencing the disc of the timing mechanism. JOHANNES ANTONIUS VAN LAMMEREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Schwarz et al J une 15, 1943 

